The present invention relates to method for producing a reversible thermochromic display. More particularly, the invention relates to a method for producing a reversible thermochromic display composed of two or more overlapping layers of image formed on a support, at least one of which layers provides a reversible thermochromic image, wherein the colored images on the respective layers have different visual densities and the reversible thermochromic image changes color at a temperature lower or higher than a predetermined point and provides a color that is more intense and more easily discernible than the pale color of the other images.
Reversible thermochromic materials are known (see U.S. Pat. No. 4,028,118), and printing inks prepared from these materials have been applied to various articles to construct temperature indicators, ornamental objects and toys that reversibly change or develop color at well-defined temperatures. However, in most commercial products that provide the viewing of multiple images at different temperatures, images that develop color in the desired temperature regions are formed on a support side by side. This not only requires a large area, but also is unappealing for the viewer.